Cretaceous sedimentary rocks of north-central Oregon previously referred to as the Hudspeth and Gable Creek formations and recently renamed the Mitchell Formation are potential petroleum source and reservoir rocks. Thus, determining their extent under the cover of Tertiary volcanics is of great importance to future petroleum exploration in the southern half of the Columbia Basin. The direction of sediment transport has been previously studied by several workers with contradicting results and conclusions. The primary objective of this research was to expand the paleocurrent analysis using both macro- and micro-fabric to provide additional evidence of sediment transport direction. This information allows a better prediction of the extent, thickness, and petroleum potential of the marine Cretaceous rocks.
From field study of both sedimentary structures and gross lithology my work reconfirms that these sediments are part of a sub-sea fan complex consisting of fan-apron-facies turbidites and mudstones (Hudspeth mudstone facies) and channel-facies conglomerates and sandstones (Gable Creek sandstone-conglomerate facies). Sole marks, flute casts, pebble imbrication, and alignment of plant fragments indicate that sediment transport was generally from south to north into a northeast-southwest elongate results suggest that the greatest potential basin. These for petroleum production from Cretaceous sediments in north-central Oregon lies in restricted rift-type basins such as those in the surrounding area of Mitchell.
","abstract_html":"<p>Cretaceous sedimentary rocks of north-central Oregon previously referred to as the Hudspeth and Gable Creek formations and recently renamed the Mitchell Formation are potential petroleum source and reservoir rocks. Thus, determining their extent under the cover of Tertiary volcanics is of great importance to future petroleum exploration in the southern half of the Columbia Basin. The direction of sediment transport has been previously studied by several workers with contradicting results and conclusions. The primary objective of this research was to expand the paleocurrent analysis using both macro- and micro-fabric to provide additional evidence of sediment transport direction. This information allows a better prediction of the extent, thickness, and petroleum potential of the marine Cretaceous rocks.</p> <p>From field study of both sedimentary structures and gross lithology my work reconfirms that these sediments are part of a sub-sea fan complex consisting of fan-apron-facies turbidites and mudstones (Hudspeth mudstone facies) and channel-facies conglomerates and sandstones (Gable Creek sandstone-conglomerate facies). Sole marks, flute casts, pebble imbrication, and alignment of plant fragments indicate that sediment transport was generally from south to north into a northeast-southwest elongate results suggest that the greatest potential basin. These for petroleum production from Cretaceous sediments in north-central Oregon lies in restricted rift-type basins such as those in the surrounding area of Mitchell.</p>","abstract_has_math":false,"creators":["Sandefur, Craig A."],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Geology","degree_department":null,"school":null,"contributors":["Lanny H. Fisk","Knut A. Andersson","H. Paul Buchheim"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1986,"date_issued":"1986-03-01T08:00:00Z","date_published":"1986-03-01T08:00:00Z","updated_at":"2026-07-24T02:52:59Z","subjects":["Geology","Sedimentology","Geology; Stratigraphic -- Cretaceous; Petroleum -- Geology -- Oregon; Sediments (Geology) -- Oregon"],"languages":["English"],"rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsrepository.llu.edu/etd/1006","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lanny H. Fisk","Knut A. Andersson","H. Paul Buchheim"]},{"key":"dc:creator","label":"Author","values":["Sandefur, Craig A."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Geology","Sedimentology","Geology; Stratigraphic -- Cretaceous; Petroleum -- Geology -- Oregon; Sediments (Geology) -- Oregon"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsrepository.llu.edu/etd/1006"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Cretaceous sedimentary rocks of north-central Oregon previously referred to as the Hudspeth and Gable Creek formations and recently renamed the Mitchell Formation are potential petroleum source and reservoir rocks. Thus, determining their extent under the cover of Tertiary volcanics is of great importance to future petroleum exploration in the southern half of the Columbia Basin. The direction of sediment transport has been previously studied by several workers with contradicting results and conclusions. The primary objective of this research was to expand the paleocurrent analysis using both macro- and micro-fabric to provide additional evidence of sediment transport direction. This information allows a better prediction of the extent, thickness, and petroleum potential of the marine Cretaceous rocks.
From field study of both sedimentary structures and gross lithology my work reconfirms that these sediments are part of a sub-sea fan complex consisting of fan-apron-facies turbidites and mudstones (Hudspeth mudstone facies) and channel-facies conglomerates and sandstones (Gable Creek sandstone-conglomerate facies). Sole marks, flute casts, pebble imbrication, and alignment of plant fragments indicate that sediment transport was generally from south to north into a northeast-southwest elongate results suggest that the greatest potential basin. These for petroleum production from Cretaceous sediments in north-central Oregon lies in restricted rift-type basins such as those in the surrounding area of Mitchell.
"]},{"key":"dc:title","label":"Title","values":["Paleocurrent Analysis of the Cretaceous Mitchell Formation, North-Central Oregon"]}]}],"canonical_facts":{"dc:contributor":["Lanny H. Fisk","Knut A. Andersson","H. Paul Buchheim"],"dc:creator":["Sandefur, Craig A."],"dc:description.abstract":["Cretaceous sedimentary rocks of north-central Oregon previously referred to as the Hudspeth and Gable Creek formations and recently renamed the Mitchell Formation are potential petroleum source and reservoir rocks. Thus, determining their extent under the cover of Tertiary volcanics is of great importance to future petroleum exploration in the southern half of the Columbia Basin. The direction of sediment transport has been previously studied by several workers with contradicting results and conclusions. The primary objective of this research was to expand the paleocurrent analysis using both macro- and micro-fabric to provide additional evidence of sediment transport direction. This information allows a better prediction of the extent, thickness, and petroleum potential of the marine Cretaceous rocks.
From field study of both sedimentary structures and gross lithology my work reconfirms that these sediments are part of a sub-sea fan complex consisting of fan-apron-facies turbidites and mudstones (Hudspeth mudstone facies) and channel-facies conglomerates and sandstones (Gable Creek sandstone-conglomerate facies). Sole marks, flute casts, pebble imbrication, and alignment of plant fragments indicate that sediment transport was generally from south to north into a northeast-southwest elongate results suggest that the greatest potential basin. These for petroleum production from Cretaceous sediments in north-central Oregon lies in restricted rift-type basins such as those in the surrounding area of Mitchell.
"],"dc:identifier":["https://scholarsrepository.llu.edu/etd/1006"],"dc:language":["English"],"dc:rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"dc:subject":["Geology","Sedimentology","Geology; Stratigraphic -- Cretaceous; Petroleum -- Geology -- Oregon; Sediments (Geology) -- Oregon"],"dc:title":["Paleocurrent Analysis of the Cretaceous Mitchell Formation, North-Central Oregon"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T02:52:59Z"}